Photoactive Compounds

ABSTRACT

The present application relates to a compound of formula 
     
       
         
         
             
             
         
       
     
     where X is selected from the group CF 3 SO 3 , C 4 F 9 SO 3 , N(SO 2 C 2 F 5 ) 2 , N(SO 2 CF 3 SO 2 C 4 F 9 ), N(SO 2 C 3 F 7 ) 2 , N(SO 2 C 4 F 9 ) 2 , CF 3 CHFO(CF 2 ) 2 SO 3 , and CH 3 CH 2 CH 2 O(CF 2 ) 4 SO 3 . A photoresist composition comprising a polymer containing an acid labile group, the above compounds, and one or more additional photoacid generators is also provided for.

FIELD OF INVENTION

The present invention relates to novel photoactive compounds useful inphotoresist compositions in the field of microlithography, andespecially useful for imaging negative and positive patterns in theproduction of semiconductor devices, as well as photoresist compositionsand processes for imaging photoresists.

BACKGROUND OF THE INVENTION

Photoresist compositions are used in microlithography processes formaking miniaturized electronic components such as in the fabrication ofcomputer chips and integrated circuits. Generally, in these processes, athin coating of film of a photoresist composition is first applied to asubstrate material, such as silicon wafers used for making integratedcircuits. The coated substrate is then baked to evaporate any solvent inthe photoresist composition and to fix the coating onto the substrate.The photoresist coated on the substrate is next subjected to animage-wise exposure to radiation.

The radiation exposure causes a chemical transformation in the exposedareas of the coated surface. Visible light, ultraviolet (UV) light,electron beam and X-ray radiant energy are radiation types commonly usedtoday in microlithographic processes. After this image-wise exposure,the coated substrate is treated with a developer solution to dissolveand remove either the radiation exposed or the unexposed areas of thephotoresist. The trend toward the miniaturization of semiconductordevices has led to the use of new photoresists that are sensitive atlower and lower wavelengths of radiation and has also led to the use ofsophisticated multilevel systems to overcome difficulties associatedwith such miniaturization.

There are two types of photoresist compositions: negative-working andpositive-working. The type of photoresist used at a particular point inlithographic processing is determined by the design of the semiconductordevice. When negative-working photoresist compositions are exposedimage-wise to radiation, the areas of the photoresist compositionexposed to the radiation become less soluble to a developer solution(e.g. a cross-linking reaction occurs) while the unexposed areas of thephotoresist coating remain relatively soluble to such a solution. Thus,treatment of an exposed negative-working resist with a developer causesremoval of the non-exposed areas of the photoresist coating and thecreation of a negative image in the coating, thereby uncovering adesired portion of the underlying substrate surface on which thephotoresist composition was deposited.

On the other hand, when positive-working photoresist compositions areexposed image-wise to radiation, those areas of the photoresistcomposition exposed to the radiation become more soluble to thedeveloper solution (e.g. a rearrangement reaction occurs) while thoseareas not exposed remain relatively insoluble to the developer solution.Thus, treatment of an exposed positive-working photoresist with thedeveloper causes removal of the exposed areas of the coating and thecreation of a positive image in the photoresist coating. Again, adesired portion of the underlying surface is uncovered.

Photoresist resolution is defined as the smallest feature, which theresist composition can transfer from the photomask to the substrate witha high degree of image edge acuity after exposure and development. Inmany leading edge manufacturing applications today, photoresistresolution on the order of less than one-half micron are necessary. Inaddition, it is almost always desirable that the developed photoresistwall profiles be near vertical relative to the substrate. Suchdemarcations between developed and undeveloped areas of the resistcoating translate into accurate pattern transfer of the mask image ontothe substrate. This becomes even more critical as the push towardminiaturization reduces the critical dimensions on the devices. In caseswhere the photoresist dimensions have been reduced to below 150 nm, theroughness of the photoresist patterns has become a critical issue. Edgeroughness, commonly known as line edge roughness, is typically observedfor line and space patterns as roughness along the photoresist line, andfor contact holes as side wall roughness. Edge roughness can haveadverse effects on the lithographic performance of the photoresist,especially in reducing the critical dimension latitude and also intransferring the line edge roughness of the photoresist to thesubstrate. Hence, photoresists that minimize edge roughness are highlydesirable.

Photoresists sensitive to short wavelengths, between about 100 nm andabout 300 nm are often used where subhalfmicron geometries are required.Particularly preferred are photoresists comprising non-aromaticpolymers, a photoacid generator, optionally a dissolution inhibitor, andsolvent.

High resolution, chemically amplified, deep ultraviolet (100-300 nm)positive and negative tone photoresists are available for patterningimages with less than quarter micron geometries. To date, there arethree major deep ultraviolet (UV) exposure technologies that haveprovided significant advancement in miniaturization, and these uselasers that emit radiation at 248 nm, 193 nm and 157 nm. Photoresistsused in the deep UV typically comprise a polymer which has an acidlabile group and which can deprotect in the presence of an acid, aphotoactive component which generates an acid upon absorption of light,and a solvent.

Photoresists for 248 nm have typically been based on substitutedpolyhydroxystyrene and its copolymers, such as those described in U.S.Pat. No. 4,491,628 and U.S. Pat. No. 5,350,660. On the other hand,photoresists for 193 nm exposure require non-aromatic polymers, sincearomatics are opaque at this wavelength. U.S. Pat. No. 5,843,624 and GB2,320,718 disclose photoresists useful for 193 nm exposure. Generally,polymers containing alicyclic hydrocarbons are used for photoresists forexposure below 200 nm. Alicyclic hydrocarbons are incorporated into thepolymer for many reasons, primarily since they have relatively highcarbon:hydrogen ratios which improve etch resistance, they also providetransparency at low wavelengths and they have relatively high glasstransition temperatures. Photoresists sensitive at 157 nm have beenbased on fluorinated polymers, which are known to be substantiallytransparent at that wavelength. Photoresists derived from polymerscontaining fluorinated groups are described in WO 00/67072 and WO00/17712.

The polymers used in a photoresist are designed to be transparent to theimaging wavelength, but on the other hand, the photoactive component hasbeen typically designed to be absorbing at the imaging wavelength tomaximize photosensitivity. The photosensitivity of the photoresist isdependent on the absorption characteristics of the photoactivecomponent, the higher the absorption, the less the energy required togenerate the acid, and the more photosensitive is the photoresist.

SUMMARY OF THE INVENTION

The present invention relates to a compound of the formula

where X is selected from the group N(SO₂C₂F₅)₂, N(SO₂CF₃SO₂C₄F₉),N(SO₂C₃F₇)₂, N(SO₂C₄F₉)₂, CF₃CHFO(CF₂)₂SO₃, and CH₃CH₂CH₂O(CF₂)₄SO₃.

In addition, the present invention relates to a photoresist compositioncomprising;

a) a polymer containing an acid labile group;

b) a compound having the formula

where X is selected from the group CF₃SO₃, C₄F₉SO₃, N(SO₂CF₃)₂,N(SO₂C₂F₅)₂, N(SO₂CF₃SO₂C₄F₉), N(SO₂C₃F₇)₂, N(SO₂C₄F₉)₂, C(SO₂CF₃)₃,CF₃CHFO(CF₂)₂SO₃, and CH₃CH₂CH₂O(CF₂)₄SO₃; and

c) one or more additional photoacid generators.

A coated substrate wherein the above composition forms a photoresistfilm thereon and a process for imaging a photoresist using the abovecomposition are also provided.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a compound of the formula

where X is selected from the group N(SO₂C₂F₅)₂, N(SO₂CF₃SO₂C₄F₉),N(SO₂C₃F₇)₂, N(SO₂C₄F₉)₂, CF₃CHFO(CF₂)₂SO₃, and CH₃CH₂CH₂O(CF₂)₄SO₃.

In addition, the present invention relates to a photoresist compositioncomprising;

a) a polymer containing an acid labile group;

b) a compound having the formula

where X is selected from the group CF₃SO₃, C₄F₉SO₃, N(SO₂CF₃)₂,N(SO₂C₂F₅)₂, N(SO₂CF₃SO₂C₄F₉), N(SO₂C₃F₇)₂, N(SO₂C₄F₉)₂, C(SO₂CF₃)₃,CF₃CHFO(CF₂)₂SO₃, and CH₃CH₂CH₂O(CF₂)₄SO₃; and

c) one or more additional photoacid generators.

A coated substrate wherein the above composition forms a photoresistfilm thereon and a process for imaging a photoresist using the abovecomposition are also provided.

For the composition, the one or more additional photoacid generators areselected from

(a) a compound of the formula

(Ai)₂ Xi1,

where each Ai is individually an organic onium cation selected from

where Ar is selected from

naphthyl, or anthryl;

Y is selected from

where R₁, R₂, R₃, R_(1A), R_(1B), R_(2A), R_(2B), R_(3A), R_(3B),R_(4A), R_(4B), R_(5A), and R_(5B) are each independently selected fromZ, hydrogen, OSO₂R₉, OR₂₀, straight or branched alkyl chain optionallycontaining one or more O atoms, monocycloalkyl or polycycloalkyl groupoptionally containing one or more O atoms, monocycloalkyl- orpolycycloalkylcarbonyl group, aryl, aralkyl, arylcarbonylmethyl group,alkoxyalkyl, alkoxycarbonylalkyl, alkylcarbonyl, monocycloalkyl- orpolycycloalkyloxycarbonylalkyl with the cycloalkyl ring optionallycontaining one or more O atoms, monocycloalkyl- orpolycycloalkyloxyalkyl with the cycloalkyl ring optionally containingone or more O atoms, straight or branched perfluoroalkyl,monocycloperfluoroalkyl or polycycloperfluoroalkyl, straight or branchedalkoxy chain, nitro, cyano, halogen, carboxyl, hydroxyl, sulfate,tresyl, or hydroxyl;R₆ and R₇ are each independently selected from straight or branchedalkyl chain optionally containing one or more O atoms, monocycloalkyl orpolycycloalkyl group optionally containing one or more O atoms,monocycloalkyl- or polycycloalkylcarbonyl group, aryl, aralkyl, straightor branched perfluoroalkyl, monocycloperfluoroalkyl orpolycycloperfluoroalkyl, arylcarbonylmethyl group, nitro, cyano, orhydroxyl or R₆ and R₇ together with the S atom to which they areattached form a 5-, 6-, or 7-membered saturated or unsaturated ringoptionally containing one or more O atoms;R₉ is selected from alkyl, fluoroalkyl, perfluoroalkyl, aryl,fluoroaryl, perfluoroaryl, monocycloalkyl or polycycloalkyl group withthe cycloalkyl ring optionally containing one or more O atoms,monocyclofluoroalkyl or polycyclofluoroalkyl group with the cycloalkylring optionally containing one or more O atoms, ormonocycloperfluoralkyl or polycycloperfluoroalkyl group with thecycloalkyl ring optionally containing one or more O atoms;R₂₀ is alkoxyalkyl, alkoxycarbonylalkyl, alkylcarbonyl, monocycloalkyl-or polycycloalkyloxycarbonylalkyl with the cycloalkyl ring optionallycontaining one or more O atoms, or monocycloalkyl- orpolycycloalkyloxyalkyl with the cycloalkyl ring optionally containingone or more O atoms;

T is a direct bond, a divalent straight or branched alkyl groupoptionally containing one or more O atoms, divalent aryl group, divalentaralkyl group, or divalent monocycloalkyl or polycycloalkyl groupoptionally containing one or more O atoms;

Z is —(V)_(j)—(C(X11)(X12))_(n)-O—C(═O)—R₈, where either (i) one of X11or X12 is straight or branched alkyl chain containing at least onefluorine atom and the other is hydrogen, halogen, or straight orbranched alkyl chain or (ii) both of X11 and X12 are straight orbranched alkyl chain containing at least one fluorine atom;V is a linkage group selected from a direct bond, a divalent straight orbranched alkyl group optionally containing one or more O atoms, divalentaryl group, divalent aralkyl group, or divalent monocycloalkyl orpolycycloalkyl group optionally containing one or more O atoms;

X2 is hydrogen, halogen, or straight or branched alkyl chain optionallycontaining one or more O atoms; R₈ is a straight or branched alkyl chainoptionally containing one or more O atoms, a monocycloalkyl orpolycycloalkyl group optionally containing one or more O atoms, or aryl;X3 is hydrogen, straight or branched alkyl chain, halogen, cyano, or—C(═O)—R₅₀ where R₅₀ is selected from straight or branched alkyl chainoptionally containing one or more O atoms or —O—R₅₁ where R₅₁ ishydrogen or straight or branched alkyl chain;

each of i and k are independently 0 or a positive integer;j is 0 to 10;m is 0 to 10;and n is 0 to 10,the straight or branched alkyl chain optionally containing one or more Oatoms, straight or branched alkyl chain, straight or branched alkoxychain, monocycloalkyl or polycycloalkyl group optionally containing oneor more O atoms, monocycloalkyl- or polycycloalkylcarbonyl group,alkoxyalkyl, alkoxycarbonylalkyl, alkylcarbonyl, monocycloalkyl- orpolycycloalkyloxycarbonylalkyl with the cycloalkyl ring optionallycontaining one or more O atoms, monocycloalkyl- orpolycycloalkyloxyalkyl with the cycloalkyl ring optionally containingone or more O atoms, aralkyl, aryl, naphthyl, anthryl, 5-, 6-, or7-membered saturated or unsaturated ring optionally containing one ormore O atoms, or arylcarbonylmethyl group being unsubstituted orsubstituted by one or more groups selected from the group consisting ofZ, halogen, alkyl, C₁₋₈ perfluoroalkyl, monocycloalkyl orpolycycloalkyl, OR₂₀, alkoxy, C₃₋₂₀ cyclic alkoxy, dialkylamino,dicyclic dialkylamino, hydroxyl, cyano, nitro, tresyl, oxo, aryl,aralkyl, oxygen atom, CF₃SO₃, aryloxy, arylthio, and groups of formulae(II) to (VI):

wherein R₁₀ and R₁₁ each independently represent a hydrogen atom, astraight or branched alkyl chain optionally containing one or more Oatoms, or a monocycloalkyl or polycycloalkyl group optionally containingone or more O atoms, or R₁₀ and R₁₁ together can represent an alkylenegroup to form a five- or six-membered ring;R₁₂ represents a straight or branched alkyl chain optionally containingone or more O atoms, a monocycloalkyl or polycycloalkyl group optionallycontaining one or more O atoms, or aralkyl, or R₁₀ and R₁₂ togetherrepresent an alkylene group which forms a five- or six-membered ringtogether with the interposing —C—O— group, the carbon atom in the ringbeing optionally substituted by an oxygen atom;

R₁₃ represents a straight or branched alkyl chain optionally containingone or more O atoms or a monocycloalkyl or polycycloalkyl groupoptionally containing one or more O atoms; R₁₄ and R₁₅ eachindependently represent a hydrogen atom, a straight or branched alkylchain optionally containing one or more O atoms or a monocycloalkyl orpolycycloalkyl group optionally containing one or more O atoms; R₁₆represents a straight or branched alkyl chain optionally containing oneor more O atoms, a monocycloalkyl or polycycloalkyl group optionallycontaining one or more O atoms, aryl, or aralkyl; and

R₁₇ represents straight or branched alkyl chain optionally containingone or more O atoms, a monocycloalkyl or polycycloalkyl group optionallycontaining one or more O atoms, aryl, aralkyl, the group —Si(R₁₆)₂R₁₇,or the group —O—Si(R₁₆)₂R₁₇, the straight or branched alkyl chainoptionally containing one or more O atoms, monocycloalkyl orpolycycloalkyl group optionally containing one or more O atoms, aryl,and aralkyl being unsubstituted or substituted as above;

Xi1 is an anion of the formula

Q-R₅₀₀—SO₃ ⁻

where Q is selected from ⁻O₃S and ⁻O₂C;R₅₀₀ is a group selected from linear or branched alkyl, cycloalkyl,aryl, or combinations thereof, optionally containing a catenary S or N,where the alkyl, cycloalkyl, and aryl groups are unsubstituted orsubstituted by one or more groups selected from the group consisting ofhalogen, unsubstituted or substituted alkyl, unsubstituted orsubstituted C₁₋₈ perfluoroalkyl, hydroxyl, cyano, sulfate, and nitro;and(b) a compound having the formula

Ai Xi2,

where Ai is an organic onium cation as previously defined and Xi2 is ananion; and mixtures of (a) and (b) thereof.

Examples of the Xi2 anion include CF₃SO₃ ⁻, CHF₂SO₃ ⁻, CH₃SO₃, CCl₃SO₃⁻, C₂F₅SO₃ ⁻, C₂HF₄SO₃ ⁻, C₄F₉SO₃ ⁻, camphor sulfonate, perfluorooctanesulfonate, benzene sulfonate, pentafluorobenzene sulfonate, toluenesulfonate, perfluorotoluene sulfonate, (Rf1SO₂)₃C⁻ and (Rf1SO₂)₂N⁻,wherein each Rf1 is independently selected from the group consisting ofhighly fluorinated or perfluorinated alkyl or fluorinated aryl radicalsand may be cyclic, when a combination of any two Rf1 groups are linkedto form a bridge, further, the Rf1 alkyl chains contain from 1-20 carbonatoms and may be straight, branched, or cyclic, such that divalentoxygen, trivalent nitrogen or hexavalent sulfur may interrupt theskeletal chain, further when Rf1 contains a cyclic structure, suchstructure has 5 or 6 ring members, optionally, 1 or 2 of which areheteroatoms, and Rg-O—Rf2-SO₃ ⁻, where Rf2 is selected from the groupconsisting of linear or branched (CF₂)_(j) where j is an integer from 4to 10 and C₁-C₁₂ cycloperfluoroalkyl divalent radical which isoptionally perfluoroC₁₋₁₀alkyl substituted, Rg is selected from thegroup consisting of C₁-C₂₀ linear, branched, monocycloalkyl orpolycycloalkyl, C₁-C₂₀ linear, branched, monocycloalkenyl orpolycycloalkenyl, aryl, and aralkyl, the alkyl, alkenyl, aralkyl andaryl groups being unsubstituted, substituted, optionally containing oneor more catenary oxygen atoms, partially fluorinated or perfluorinated.Examples of such anions Xi2 include (C₂F₅SO₂)₂N⁻, (C₄F₉SO₂)₂N⁻,(C₈F₁₇SO₂)₃C⁻, (CF₃SO₂)₃C⁻, (CF₃SO₂)₂N⁻, (CF₃SO₂)₂(C₄F₉SO₂)C⁻,(C₂F₅SO₂)₃C⁻, (C₄F₉SO₂)₃C⁻, (CF₃SO₂)₂(C₂F₅SO₂)C⁻, (C₄F₉SO₂)(C₂F₅SO₂)₂C⁻,(CF₃SO₂)(C₄F₉SO₂)N⁻, [(CF₃)₂NC₂F₄SO₂]₂N⁻, (CF₃)₂NC₂F₄SO₂C⁻ (SO₂CF₃)₂,(3,5-bis(CF₃)C₆H₃)SO₂N⁻SO₂CF₃, C₆F₅SO₂C⁻ (SO₂CF₃)₂, C₆F₅SO₂N⁻SO₂CF₃,

CF₃CHFO(CF₂)₄SO₃ ⁻, CF₃CH₂O(CF₂)₄SO₃ ⁻, CH₃CH₂O(CF₂)₄SO₃ ⁻,CH₃CH₂CH₂O(CF₂)₄SO₃ ⁻, CH₃O(CF₂)₄SO₃ ⁻, C₂H₅O(CF₂)₄SO₃ ⁻, C₄H₉O(CF₂)₄SO₃⁻, C₆H₅CH₂O(CF₂)₄SO₃ ⁻, C₂H₅OCF₂CF(CF₃)SO₃ ⁻, CH₂═CHCH₂O(CF₂)₄SO₃ ⁻,CH₃OCF₂CF(CF₃)SO₃ ⁻, C₄H₉OCF₂CF(CF₃)SO₃ ⁻, C₈H₁₇O(CF₂)₂SO₃ ⁻, andC₄H₉O(CF₂)₂SO₃ ⁻. Other examples of suitable anions can be found in U.S.Pat. No. 6,841,333 and U.S. Pat. No. 5,874,616.

Examples of Ai Xi2 include bis(4-t-butylphenyl)iodoniumbis-perfluoroethane sulfonimide, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluorobutane sulfonate,triphenylsulfonium trifluromethane sulfonate, triphenylsulfoniumnonafluorobutane sulfonate, 4-(1-butoxyphenyl)diphenylsulfoniumbis-(perfluorobutanesulfonyl)imide, 4-(1-butoxyphenyl)diphenylsulfoniumbis-(perfluoroethanesulfonyl)imide,2,4,6-trimethylphenyldiphenylsulfoniumbis-perfluorobutanesulfonyl)imide,2,4,6-trimethylphenyldiphenylsulfoniumbis-(perfluoroethanesulfonyl)imide, toluenediphenylsulfoniumbis-(perfluorobutanesulfonyl)imide, toluenediphenylsulfoniumbis(perfluoroethanesulfonyl)imide,toluenediphenylsulfonium-(trifluoromethyl perfluorobutylsulfonyl)imide,tris-(tert-butylphenyl)sulfonium-(trifluoromethylperfluorobutylsulfonyl)imide, tris-(tert-butylphenyl)sulfoniumbis-(perfluorobutanesulfonyl)imide,tris-(tert-butylphenyl)sulfonium-bis-(trifluoromethanesulfonyl)imide,and the like as well as other photoacid generators known to thoseskilled in the art.

The term alkyl as used herein means a straight or branched chainhydrocarbon. Representative examples of alkyl include, but are notlimited to, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl,iso-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl,3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, n-heptyl,n-octyl, n-nonyl, and n-decyl.

Alkylene refers to divalent alkyl radicals, which can be linear orbranched, such as, for example, methylene, ethylene, propylene, butyleneor the like.

By the term aryl is meant a radical derived from an aromatic hydrocarbonby the elimination of one atom of hydrogen and can be substituted orunsubstituted. The aromatic hydrocarbon can be mononuclear orpolynuclear. Examples of aryl of the mononuclear type include phenyl,tolyl, xylyl, mesityl, cumenyl, and the like. Examples of aryl of thepolynuclear type include naphthyl, anthryl, phenanthryl, and the like.The aryl group can be unsubstituted or substituted as provided forhereinabove.

The term alkoxy refers to a group of alkyl-O—, where alkyl is definedherein. Representative examples of alkoxy include, but are not limitedto, methoxy, ethoxy, propoxy, 2-propoxy, butoxy, tert-butoxy, pentyloxy,and hexyloxy.

The term aryloxy refers to a group of aryl-O—, where aryl is definedherein.

By the term aralkyl is meant an alkyl group containing an aryl group. Itis a hydrocarbon group having both aromatic and aliphatic structures,that is, a hydrocarbon group in which a lower alkyl hydrogen atom issubstituted by a mononuclear or polynuclear aryl group. Examples ofaralkyl groups include, without limitation, benzyl, 2-phenyl-ethyl,3-phenyl-propyl, 4-phenyl-butyl, 5-phenyl-pentyl, 4-phenylcyclohexyl,4-benzylcyclohexyl, 4-phenylcyclohexylmethyl, 4-benzylcyclohexylmethyl,naphthylmethyl, and the like.

The term monocycloalkyl as used herein, refers to an optionallysubstituted, saturated or partially unsaturated monocycloalkyl ringsystem, where if the ring is partially unsaturated, it is then amonocycloalkenyl group. The term polycycloalkyl as used herein refers toan optionally substituted, saturated or partially unsaturatedpolycycloalkyl ring system containing two or more rings, where if thering is partially unsaturated, it is then a polycycloalkenyl group.Examples of monocycloalkyl or polycycloalkyl groups optionallycontaining one or more O atoms are well know to those skilled in the artand include, for example, cyclopropyl, cyclobutyl, cyclopentyl,cycloheptyl, cyclohexyl, 2-methyl-2-norbornyl, 2-ethyl-2-norbornyl,2-methyl-2-isobornyl, 2-ethyl-2-isobornyl, 2-methyl-2-adamantyl,2-ethyl-2-adamantyl, 1-adamantyl-1-methylethyl, adamantyl,tricyclodecyl, 3-oxatricyclo[4.2.1.0^(2,5)]nonyl, tetracyclododecanyl,tetracyclo[5.2.2.0.0]undecanyl, bornyl, isobornyl norbornyl lactone,adamantyl lactone and the like.

The term alkoxycarbonylalkyl embraces alkyl radicals substituted with analkoxycarbonyl radical as defined herein. Examples ofalkoxycarbonylalkyl radicals include methoxycarbonyl methyl[CH₃O—C(═O)—CH₂—], ethoxycarbonyl methyl [CH₃CH₂O—C(═O)—CH₂—],methoxycarbonylethyl [CH₃O—C(═O)—CH₂CH₂—], and ethoxycarbonylethyl[CH₃CH₂O—C(═O)—CH₂CH₂—].

The term alkylcarbonyl as used herein means an alkyl group, as definedherein, appended to the parent molecular moiety through a carbonylgroup, as defined herein, which can be generically represented asalkyl-C(O)—. Representative examples of alkylcarbonyl include, but arenot limited to acetyl (methyl carbonyl), butyryl (propylcarbonyl),octanoyl (heptylcarbonyl), dodecanoyl (undecylcarbonyl), and the like.

Alkoxycarbonyl means alkyl-O—C(O)—, wherein alkyl is as previouslydescribed. Non-limiting examples include methoxycarbonyl [CH₃O—C(O)—]and the ethoxycarbonyl [CH₃CH₂O—C(O)—], benzyloxycarbonyl[C₆H₅CH₂O—C(O)—] and the like.

Alkoxyalkyl means that a terminal alkyl group is linked through an etheroxygen atom to an alkyl moiety, which can be generically represented asalkyl-O-alkyl wherein the alkyl groups can be linear or branched.Examples of alkoxyalkyl include, but are not limited to, methoxypropyl,methoxybutyl, ethoxypropyl, methoxymethyl

Monocycloalkyl- or polycycloalkyloxycarbonylalkyl means that a terminalmonocycloalkyl or polycycloalkyl group is linked through —O—C(═O)— to analkyl moiety, generically represented as monocycloalkyl- orpolycycloalkyl-O—C(═O)-alkyl.

Monocycloalkyl- or polycycloalkyloxyalkyl means that a terminalmonocycloalkyl or polycycloalkyl group is linked through an ether oxygenatom to an alkyl moiety, which can be generically represented asmonocycloalkyl- or polycycloalkyl-O-alkyl.

Monocyclofluoroalkyl- or polycyclofluoroalkyl means a monocyclalkyl- orpolycycloalkyl group substituted with one or more fluorine atoms.

Polymers useful in the photoresist compositions include those that haveacid labile groups that make the polymer insoluble in aqueous alkalinesolution, but such a polymer in the presence of an acid catalyticallydeprotects the polymer, wherein the polymer then becomes soluble in anaqueous alkaline solution. The polymers preferably are transparent below200 nm, and are essentially non-aromatic, and preferably are acrylatesand/or cycloolefin polymers. Such polymers are, for example, but notlimited to, those described in U.S. Pat. No. 5,843,624, U.S. Pat. No.5,879,857, WO 97/33,198, EP 789,278 and GB 2,332,679. Nonaromaticpolymers that are preferred for irradiation below 200 nm are substitutedacrylates, cycloolefins, substituted polyethylenes, etc. Aromaticpolymers based on polyhydroxystyrene and its copolymers may also beused, especially for 248 nm exposure.

Polymers based on acrylates are generally based on poly(meth)acrylateswith at least one unit containing pendant alicyclic groups, and with theacid labile group being pendant from the polymer backbone and/or fromthe alicyclic group. Examples of pendant alicyclic groups, may beadamantyl, tricyclodecyl, isobornyl, menthyl and their derivatives.Other pendant groups may also be incorporated into the polymer, such asmevalonic lactone, gamma butyrolactone, alkyloxyalkyl, etc. Examples ofstructures for the alicyclic group include:

The type of monomers and their ratios incorporated into the polymer areoptimized to give the best lithographic performance. Such polymers aredescribed in R. R. Dammel et al., Advances in Resist Technology andProcessing, SPIE, Vol. 3333, p 144, (1998). Examples of these polymersinclude poly(2-methyl-2-adamantyl methacrylate-co-mevalonic lactonemethacrylate), poly(carboxy-tetracyclododecylmethacrylate-co-tetrahydropyranylcarboxytetracyclododecyl methacrylate),poly(tricyclodecyl acrylate-co-tetrahydropyranylmethacrylate-co-methacrylic acid), poly(3-oxocyclohexylmethacrylate-co-adamantyl methacrylate).

Polymers synthesized from cycloolefins, with norbornene andtetracyclododecene derivatives, may be polymerized by ring-openingmetathesis, free-radical polymerization or using metal organiccatalysts. Cycloolefin derivatives may also be copolymerized with cyclicanhydrides or with maleimide or its derivatives. Examples of cyclicanhydrides are maleic anhydride (MA) and itaconic anhydride. Thecycloolefin is incorporated into the backbone of the polymer and may beany substituted or unsubstituted multicyclic hydrocarbon containing anunsaturated bond. The monomer can have acid labile groups attached. Thepolymer may be synthesized from one or more cycloolefin monomers havingan unsaturated bond. The cycloolefin monomers may be substituted orunsubstituted norbornene, or tetracyclododecane. The substituents on thecycloolefin may be aliphatic or cycloaliphatic alkyls, esters, acids,hydroxyl, nitrile or alkyl derivatives. Examples of cycloolefinmonomers, without limitation, include:

Other cycloolefin monomers which may also be used in synthesizing thepolymer are:

Such polymers are described in the following reference and incorporatedherein, M-D. Rahman et al, Advances in Resist Technology and Processing,SPIE, Vol. 3678, p 1193, (1999). Examples of these polymers includepoly((t-butyl-5-norbornene-2-carboxylate-co-2-hydroxyethyl-5-norbornene-2-carboxylate-co-5-norbornene-2-carboxylicacid-co-maleic anhydride),poly(t-butyl-5-norbornene-2-carboxylate-co-isobornyl-5-norbornene-2-carboxylate-co-2-hydroxyethyl-5-norbornene-2-carboxylate-co-5-norbornene-2-carboxylicacid-co-maleic anhydride),poly(tetracyclododecene-5-carboxylate-co-maleic an hydride),poly(t-butyl-5-norbornene-2-carboxylate-co-maleicanhydride-co-2-methyladamantyl methacrylate-co-2-mevalonic lactonemethacrylate), poly(2-methyladamantyl methacrylate-co-2-mevaloniclactone methacylate) and the like.

Polymers containing mixtures of (meth)acrylate monomers, cycloolefinicmonomers and cyclic anhydrides, where such monomers are described above,may also be combined into a hybrid polymer. Examples of cycloolefinmonomers include those selected from t-butyl norbornene carboxylate(BNC), hydroxyethyl norbornene carboxylate (HNC), norbornene carboxylicacid (NC),t-butyltetracyclo[4.4.0.1.^(2,6)1.^(7,10)]dodec-8-ene-3-carboxylate, andt-butoxy carbonylmethyltetracyclo[4.4.0.1.^(2,6)1.^(7,10)]dodec-8-ene-3-carboxylate. In someinstances, preferred examples of cycloolefins include t-butyl norbornenecarboxylate (BNC), hydroxyethyl norbornene carboxylate (HNC), andnorbornene carboxylic acid (NC). Examples of (meth)acrylate monomersinclude those selected from mevalonic lactone methacrylate (MLMA),2-methyl-2-adamantyl methacrylate (MAdMA), 2-adamantyl methacrylate(AdMA), 2-methyl-2-adamantyl acrylate (MAdA), 2-ethyl-2-adamantylmethacrylate (EAdMA), 3,5-dimethyl-7-hydroxy adamantyl methacrylate(DMHAdMA), adamantyl methyloxy methyl methacrylate (AdOMMA),isoadamantyl methacrylate, hydroxy-1-methacryloxyadamatane (HAdMA; forexample, hydroxy at the 3-position), hydroxy-1-adamantyl acrylate (HADA;for example, hydroxy at the 3-position), ethylcyclopentylacrylate(ECPA), ethylcyclopentylmethacrylate (ECPMA),tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate (TCDMA),3,5-dihydroxy-1-methacryloxyadamantane (DHAdMA),β-methacryloxy-γ-butyrolactone, α- or β-gamma-butyrolactone methacrylate(either α- or β-GBLMA), 5-methacryloyloxy-2,6-norbornanecarbolactone(MNBL), 5-acryloyloxy-2,6-norbornanecarbolactone (ANBL), isobutylmethacrylate (IBMA), α-gamma-butyrolactone acrylate (α-GBLA),spirolactone (meth)acrylate, oxytricyclodecane (meth)acrylate,adamantane lactone (meth)acrylate, and α-methacryloxy-γ-butyrolactone,among others. Examples of polymers formed with these monomers includepoly(2-methyl-2-adamantyl methacrylate-co-2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-α-gamma-butyrolactonemethacrylate); poly(2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate); poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate); poly(t-butyl norbornene carboxylate-co-maleicanhydride-co-2-methyl-2-adamantyl methacrylate-co-β-gamma-butyrolactonemethacrylate-co-methacryloyloxy norbornene methacrylate);poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-β-gamma-butyrolactone methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-methyl-2-adamantylmethacrylate-co-3,5-dihydroxy-1-methacryloxyadamantane-co-α-gamma-butyrolactonemethacrylate); poly(2-methyl-2-adamantylmethacrylate-co-3,5-dimethyl-7-hydroxy adamantylmethacrylate-co-α-gamma-butyrolactone methacrylate);poly(2-methyl-2-adamantylacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-α-gamma-butyrolactonemethacrylate); poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-methyl-2-adamantyl methacrylate-co-β-gamma-butyrolactonemethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-ethylcyclopentylacrylate);poly(2-methyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactone methacrylate);poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-α-gamma-butyrolactonemethacrylate-co-2-ethyl-2-adamantyl methacrylate);poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-methyl-2-adamantyl methacrylate-co-2-ethyl-2-adamantylmethacrylate-co-β-gam ma-butyrolactonemethacrylate-co-3-hydroxy-1-methacryloxyadamantane);poly(2-methyl-2-adamantyl methacrylate-co-2-ethyl-2-adamantylmethacrylate-co-α-gamma-butyrolactonemethacrylate-co-3-hydroxy-1-methacryloxyadamantane);poly(2-methyl-2-adamantyl methacrylate-co-methacryloyloxy norbornenemethacrylate-co-β-gamma-butyrolactone methacrylate);poly(ethylcyclopentylmethacrylate-co-2-ethyl-2-adamantylmethacrylate-co-α-gamma-butyrolactone acrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-isobutyl methacrylate-co-α-gamma-butyrolactone acrylate);poly(2-methyl-2-adamantyl methacrylate-co-β-gamma-butyrolactonemethacrylate-co-3-hydroxy-1-adamantylacrylate-co-tricyclo[5,2,1,02,6]deca-8-yl methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactone acrylate); poly(2-methyl-2-adamantylmethacrylate-co-βgamma-butyrolactone methacrylate-co-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamatane);poly(2-methyl-2-adamantyl methacrylate-co-methacryloyloxy norbornenemethacrylate-co-β-gamma-butyrolactone methacrylate-co-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamatane);poly(2-methyl-2-adamantyl methacrylate-co-methacryloyloxy norbornenemethacrylate-co-tricyclo[5,2,1,02,6]deca-8-ylmethacrylate-co-3-hydroxy-1-methacryloxyadamatane-co-α-gamma-butyrolactonemethacrylate); poly(2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-adamantylacrylate-co-tricyclo[5,2,1,02,6]deca-8-ylmethacrylate-co-α-gamma-butyrolactone methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactone acrylate); poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamatane-co-α-gamma-butyrolactonemethacrylate-co-2-ethyl-2-adamantyl-co-methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactone methacrylate);poly(2-methyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-5-acryloyloxy-2,6-norbornanecarbolactone);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactone methacrylate-co-α-gamma-butyrolactoneacrylate); poly(2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-adamantyl acrylate-co-α-gamma-butyrolactonemethacrylate-co-2-adamantyl methacrylate); and poly(2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-adamantyl acrylate-co-α-gamma-butyrolactoneacrylate-co-tricyclo[5,2,1,02,6]deca-8-yl methacrylate).

Other examples of suitable polymers include those described in U.S. Pat.Nos. 6,610,465, 6,120,977, 6,136,504, 6,013,416, 5,985,522, 5,843,624,5,693,453, 4,491,628, WO 00/25178, WO 00/67072, JP 2000-275845, JP2000-137327, and JP 09-73173 which are incorporated herein by reference.Blends of one or more photoresist resins may be used. Standard syntheticmethods are typically employed to make the various types of suitablepolymers. Procedures or references to suitable standard procedures(e.g., free radical polymerization) can be found in the aforementioneddocuments.

The cycloolefin and the cyclic anhydride monomer are believed to form analternating polymeric structure, and the amount of the (meth)acrylatemonomer incorporated into the polymer can be varied to give the optimallithographic properties. The percentage of the (meth)acrylate monomerrelative to the cycloolefin/anhydride monomers within the polymer rangesfrom about 95 mole % to about 5 mole %, further ranging from about 75mole % to about 25 mole %, and also further ranging from about 55 mole %to about 45 mole %.

Fluorinated non-phenolic polymers, useful for 157 nm exposure, alsoexhibit line edge roughness and can benefit from the use of the novelmixture of photoactive compounds described in the present invention.Such polymers are described in WO 00/17712 and WO 00/67072 andincorporated herein by reference. Example of one such polymer ispoly(tetrafluoroethylene-co-norbornene-co-5-hexafluoroisopropanol-substituted2-norbornene.

Polymers synthesized from cycloolefins and cyano containing ethylenicmonomers are described in the U.S. Pat. No. 6,686,429, the contents ofwhich are hereby incorporated herein by reference, may also be used.

The molecular weight of the polymers is optimized based on the type ofchemistry used and on the lithographic performance desired. Typically,the weight average molecular weight is in the range of 3,000 to 30,000and the polydispersity is in the range 1.1 to 5, preferably 1.5 to 2.5.

Other polymers of interest include those found and described in U.S.patent application Ser. No. 10/371,262, filed Feb. 21, 2003, now filedas U.S. patent application Ser. No. 10/658,840, filed Dec. 17, 2003 (andpublished now as US patent application publication no. 2004/0166433, thecontents of which are incorporated herein by reference. Still otherpolymers, such as those disclosed in U.S. patent application Ser. No.10/440,452, filed May 16, 2003 titled “Photoresist Composition for DeepUV and Process Thereof”, the contents of which are hereby incorporatedherein by reference, may also be used.

The solid components of the present invention are dissolved in anorganic solvent. The amount of solids in the solvent or mixture ofsolvents ranges from about 1 weight % to about 50 weight %. The polymermay be in the range of 5 weight % to 90 weight % of the solids and thephotoacid generator may be in the range of 1 weight % to about 50 weight% of the solids. Suitable solvents for such photoresists may include forexample ketones such as acetone, methyl ethyl ketone, methyl isobutylketone, cyclohexanone, isophorone, methyl isoamyl ketone, 2-heptanone4-hydroxy, and 4-methyl 2-pentanone; C₁ to C₁₀ aliphatic alcohols suchas methanol, ethanol, and propanol; aromatic group containing-alcoholssuch as benzyl alcohol; cyclic carbonates such as ethylene carbonate andpropylene carbonate; aliphatic or aromatic hydrocarbons (for example,hexane, toluene, xylene, etc and the like); cyclic ethers, such asdioxane and tetrahydrofuran; ethylene glycol; propylene glycol; hexyleneglycol; ethylene glycol monoalkylethers such as ethylene glycolmonomethylether, ethylene glycol monoethylether; ethylene glycolalkylether acetates such as methylcellosolve acetate and ethylcellosolveacetate; ethylene glycol dialkylethers such as ethylene glycoldimethylether, ethylene glycol diethylether, ethylene glycolmethylethylether, diethylene glycol monoalkylethers such as diethyleneglycol monomethylether, diethylene glycol monoethylether, and diethyleneglycol dimethylether; propylene glycol monoalkylethers such as propyleneglycol methylether, propylene glycol ethylether, propylene glycolpropylether, and propylene glycol butylether; propylene glycolalkyletheracetates such as propylene glycol methylether acetate,propylene glycol ethylether acetate, propylene glycol propyletheracetate, and propylene glycol butylether acetate; propylene glycolalkyletherpropionates such as propylene glycol methyletherpropionate,propylene glycol ethyletherpropionate, propylene glycolpropyletherpropionate, and propylene glycol butyletherpropionate;2-methoxyethyl ether (diglyme); solvents that have both ether andhydroxy moieties such as methoxy butanol, ethoxy butanol, methoxypropanol, and ethoxy propanol; esters such as methyl acetate, ethylacetate, propyl acetate, and butyl acetate methyl-pyruvate, ethylpyruvate; ethyl 2-hydroxy propionate, methyl 2-hydroxy 2-methylpropionate, ethyl 2-hydroxy 2-methyl propionate, methyl hydroxy acetate,ethyl hydroxy acetate, butyl hydroxy acetate, methyl lactate, ethyllactate, propyl lactate, butyl lactate, methyl 3-hydroxy propionate,ethyl 3-hydroxy propionate, propyl 3-hydroxy propionate, butyl 3-hydroxypropionate, methyl 2-hydroxy 3-methyl butanoic acid, methyl methoxyacetate, ethyl methoxy acetate, propyl methoxy acetate, butyl methoxyacetate, methyl ethoxy acetate, ethyl ethoxy acetate, propyl ethoxyacetate, butyl ethoxy acetate, methyl propoxy acetate, ethyl propoxyacetate, propyl propoxy acetate, butyl propoxy acetate, methyl butoxyacetate, ethyl butoxy acetate, propyl butoxy acetate, butyl butoxyacetate, methyl 2-methoxy propionate, ethyl 2-methoxy propionate, propyl2-methoxy propionate, butyl 2-methoxy propionate, methyl2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate,butyl 2-ethoxypropionate, methyl 2-butoxypropionate, ethyl2-butoxypropionate, propyl 2-butoxypropionate, butyl 2-butoxypropionate,methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl3-methoxypropionate, butyl 3-methoxypropionate, methyl3-ethoxypropionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate,butyl 3-ethoxypropionate, methyl 3-propoxypropionate, ethyl3-propoxypropionate, propyl 3-propoxypropionate, butyl3-propoxypropionate, methyl 3-butoxypropionate, ethyl3-butoxypropionate, propyl 3-butoxypropionate, and butyl3-butoxypropionate; oxyisobutyric acid esters, for example,methyl-2-hydroxyisobutyrate, methyl α-methoxyisobutyrate, ethylmethoxyisobutyrate, methyl α-ethoxyisobutyrate, ethylα-ethoxyisobutyrate, methyl β-methoxyisobutyrate, ethylβ-methoxyisobutyrate, methyl β-ethoxyisobutyrate, ethylβ-ethoxyisobutyrate, methyl β-isopropoxyisobutyrate, ethylβ-isopropoxyisobutyrate, isopropyl β-isopropoxyisobutyrate, butylβ-isopropoxyisobutyrate, methyl β-butoxyisobutyrate, ethylβ-butoxyisobutyrate, butyl β-butoxyisobutyrate, methylα-hydroxyisobutyrate, ethyl α-hydroxyisobutyrate, isopropylα-hydroxyisobutyrate, and butyl α-hydroxyisobutyrate; solvents that haveboth ether and hydroxy moieties such as methoxy butanol, ethoxy butanol,methoxy propanol, and ethoxy propanol; and other solvents such asdibasic esters, and gamma-butyrolactone; a ketone ether derivative suchas diacetone alcohol methyl ether; a ketone alcohol derivative such asacetol or diacetone alcohol; lactones such as butyrolactone; an amidederivative such as dimethylacetamide or dimethylformamide, anisole, andmixtures thereof.

Various other additives such as colorants, non-actinic dyes,anti-striation agents, plasticizers, adhesion promoters, dissolutioninhibitors, coating aids, photospeed enhancers, additional photoacidgenerators, and solubility enhancers (for example, certain small levelsof solvents not used as part of the main solvent (examples of whichinclude glycol ethers and glycol ether acetates, valerolactone, ketones,lactones, and the like), and surfactants may be added to the photoresistcomposition before the solution is coated onto a substrate. Surfactantsthat improve film thickness uniformity, such as fluorinated surfactants,can be added to the photoresist solution. A sensitizer that transfersenergy from a particular range of wavelengths to a different exposurewavelength may also be added to the photoresist composition. Often basesare also added to the photoresist to prevent t-tops or bridging at thesurface of the photoresist image. Examples of bases are amines, ammoniumhydroxide, and photosensitive bases. Particularly preferred bases aretrioctylamine, diethanolamine and tetrabutylammonium hydroxide.

The prepared photoresist composition solution can be applied to asubstrate by any conventional method used in the photoresist art,including dipping, spraying, and spin coating. When spin coating, forexample, the photoresist solution can be adjusted with respect to thepercentage of solids content, in order to provide coating of the desiredthickness, given the type of spinning equipment utilized and the amountof time allowed for the spinning process. Suitable substrates includesilicon, aluminum, polymeric resins, silicon dioxide, doped silicondioxide, silicon nitride, tantalum, copper, polysilicon, ceramics,aluminum/copper mixtures; gallium arsenide and other such Group III/Vcompounds. The photoresist may also be coated over antireflectivecoatings.

The photoresist coatings produced by the described procedure areparticularly suitable for application to silicon/silicon dioxide wafers,such as are utilized in the production of microprocessors and otherminiaturized integrated circuit components. An aluminum/aluminum oxidewafer can also be used. The substrate may also comprise variouspolymeric resins, especially transparent polymers such as polyesters.

The photoresist composition solution is then coated onto the substrate,and the substrate is treated (baked) at a temperature from about 70° C.to about 150° C. for from about 30 seconds to about 180 seconds on a hotplate or for from about 15 to about 90 minutes in a convection oven.This temperature treatment is selected in order to reduce theconcentration of residual solvents in the photoresist, while not causingsubstantial thermal degradation of the solid components. In general, onedesires to minimize the concentration of solvents and this firsttemperature. Treatment (baking) is conducted until substantially all ofthe solvents have evaporated and a thin coating of photoresistcomposition, on the order of half a micron (micrometer) in thickness,remains on the substrate. In a preferred embodiment the temperature isfrom about 95° C. to about 120° C. The treatment is conducted until therate of change of solvent removal becomes relatively insignificant. Thefilm thickness, temperature and time selection depends on thephotoresist properties desired by the user, as well as the equipmentused and commercially desired coating times. The coated substrate canthen be imagewise exposed to actinic radiation, e.g., ultravioletradiation, at a wavelength of from about 100 nm (nanometers) to about300 nm, x-ray, electron beam, ion beam or laser radiation, in anydesired pattern, produced by use of suitable masks, negatives, stencils,templates, etc.

The photoresist is then subjected to a post exposure second baking orheat treatment before development. The heating temperatures may rangefrom about 90° C. to about 150° C., more preferably from about 100° C.to about 130° C. The heating may be conducted for from about 30 secondsto about 2 minutes, more preferably from about 60 seconds to about 90seconds on a hot plate or about 30 to about 45 minutes by convectionoven.

The exposed photoresist-coated substrates are developed to remove theimage-wise exposed areas by immersion in a developing solution ordeveloped by spray development process. The solution is preferablyagitated, for example, by nitrogen burst agitation. The substrates areallowed to remain in the developer until all, or substantially all, ofthe photoresist coating has dissolved from the exposed areas. Developersinclude aqueous solutions of ammonium or alkali metal hydroxides. Onepreferred developer is an aqueous solution of tetramethyl ammoniumhydroxide. After removal of the coated wafers from the developingsolution, one may conduct an optional post-development heat treatment orbake to increase the coating's adhesion and chemical resistance toetching conditions and other substances. The post-development heattreatment can comprise the oven baking of the coating and substratebelow the coating's softening point or UV hardening process. Inindustrial applications, particularly in the manufacture ofmicrocircuitry units on silicon/silicon dioxide-type substrates, thedeveloped substrates may be treated with a buffered, hydrofluoric acidbase etching solution or dry etching. Prior to dry etching thephotoresist may be treated to electron beam curing in order to increasethe dry-etch resistance of the photoresist.

The invention further provides a method for producing a semiconductordevice by producing a photo-image on a substrate by coating a suitablesubstrate with a photoresist composition. The subject process comprisescoating a suitable substrate with a photoresist composition and heattreating the coated substrate until substantially all of the photoresistsolvent is removed; image-wise exposing the composition and removing theimage-wise exposed areas of such composition with a suitable developer.

The following examples provide illustrations of the methods of producingand utilizing the present invention. These examples are not intended,however, to limit or restrict the scope of the invention in any way andshould not be construed as providing conditions, parameters or valueswhich must be utilized exclusively in order to practice the presentinvention. Unless otherwise specified, all parts and percents are byweight.

EXAMPLE 1 Synthesis of octyloxyphenylphenyl iodonum bis perfluoroethanesulfonamide

4-octyloxyphenylphenyl iodonium chloride (5.31 g) was dissolved in waterand THF in a beaker and a solution of bis-perfluoroethane sulfonamideacid, 3.42 g in water and THF, was added with stirring. After six hours,chloroform (150 ml) was added and the mixture was stirred for 3 hours.The mixture was then poured into a separatory funnel and allowed toseparate into two layers (chloroform and water). The chloroform layerwas washed several times with water, dried over anhydrous sodiumsulfate, filtered and the remaining solvent was evaporated to leave anoil (8.5 g).

EXAMPLE 2 Synthesis of 4-octyloxyphenylphenyl iodonumpropyloxyperfluorobutane sulfonate

4-octyloxyphenylphenyl iodonium chloride (11.43 g) was dissolved inwater and THF in a beaker and a solution of propyloxyperfluorobutanelithium sulfonate (8.9 g) in water solution was added on stirring. Aftersix hours, chloroform (200 ml) was added and stirred for 3 hours. Thechloroform layer was washed several times with water, dried overanhydrous sodium sulfate, filtered, evaporated to oil which was added tohexane (500 ml), and a precipitate formed. The precipitate was filteredand re-dissolved in dichloromethane and precipitated in hexane,filtered, dried in the vacuum oven, yielding 12.5 g of product; mp 80°C.

Following the procedure in Example 1, but using the respective acid orsalt form of the anion, the following compounds can be made:

-   Octyloxyphenylphenyl iodonium perfluoromethane perfluorobutane    sulfonamide-   Octyloxyphenylphenyl iodonium bis perfluoropropane sulfonamide-   Octyloxyphenylphenyl iodonium bis perfluorobutane sulfonamide-   Octyloxyphenylphenyl iodonium    1,1,1,2-tetrafluoethoxy-perfluoroethylsulfonate-   Octyloxyphenylphenyl iodonium bis-perfluoromethane sulfonamide-   Octyloxyphenylphenyl iodonium tris-perfluoromethane sulfonamethide-   Octyloxyphenylphenyl iodonium perfluormethane sulfate-   Octyloxyphenylphenyl iodonium perfluorobutane sulfate-   Octyloxyphenylphenyl iodonium propyloxy-perfluorobutylsulfonate

EXAMPLE 3 Synthesis of 4-Octyloxyphenylphenyl iodonium perfluorobutanesulfonate

4-octyloxyphenylphenyl iodonium chloride (15.34 g) was dissolved inwater and THF in a beaker and a solution of potassium perfluorobutanesulfonate (11.67 g) in water and THF solution was added on stirring.After six hours, chloroform (200 ml) was added and stirred for 3 hours.The chloroform layer was washed several times with water, dried overanhydrous sodium sulfate, filtered, evaporated to oil which was added tohexane (500 ml), and a precipitate formed. The precipitate was filteredand re-dissolved in dichloromethane and precipitated in hexane,filtered, dried in the vacuum oven, yielding 22.0 g of product.

EXAMPLE 4

1.98 g of poly(EAdMA/AdOMA/HAdA/α-GBLMA/AdMA; 20/10/20/40/10) polymer,0.0168 g (15 μmol/g) of triphenylsulfonium nonaflate and 0.0588 g (37.5μmol/g) of octyloxyphenylphenyl iodonum bis perfluoroethane sulfonamidefrom Example 1, 0.6476 g of DIPA 1 weight % in PGMEA) and 0.6476 g of 10weight % PGMEA solution of a surfactant (fluoroaliphatic polymericester, supplied by 3M Corporation, St. Paul Minn.) were dissolved in27.92 g of AZ Thinner to give a 30 g photoresist solution.

EXAMPLE 5

A silicon substrate coated with a bottom antireflective coating(B.A.R.C.) was prepared by spin coating the bottom anti-reflectivecoating solution (AZ® EXP ArF-1, B.A.R.C. available from AZ ElectronicMaterials USA Corp., Somerville, N.J.) onto the silicon substrate andbaking at 215° C. for 60 sec. The B.A.R.C film thickness was 29 nm. Thephotoresist solution from Example 4 was then coated on the B.A.R.Ccoated silicon substrate. The spin speed was adjusted such that thephotoresist film thickness was 180 nm, soft baked at 100° C./60 s,exposed with Nikon 306D 0.85NA & ⅘ Annular Illumination, PEB 110° C./60s, Development time: 30 s (ACT12), 6% PSM. The imaged photoresist wasthen developed using a 2.38 weight % aqueous solution of tetramethylammonium hydroxide for 30 sec. The line and space patterns were thenobserved on a scanning electron microscope. The photoresist had aphotosensitivity of 47.6 mJ/cm² and had very good exposure latitude(16.8%), good LER and profile shape.

EXAMPLE 6

2.62 g of poly(EAdMA/ECPMA/HAdA/α-GBLMA; 15/15/30/40) polymer, 0.0469 gof bis(t-butyldiphenyl)iodonium octafluorobutane disulfonate, 0.0488 gof octyloxyphenylphenyl iodonum bis perfluoroethane sulfonamide fromExample 1. and 0.0363 g of bis(triphenylsulfonium)octafluorobutanedisulfonate, 0.0032 g of 2,6-diisopropylaniline and 0.0037 g ofN-(t-butoxycarbonyl-L-alanine)methylester, 0.0048 g of a surfactant(fluoroaliphatic polymeric ester, supplied by 3M Corporation, St. PaulMinn.) were dissolved in 37.2 g of mixed solvent (2-hydroxy isobutyricacid methylester (MHIB)/1-methoxy-2-propanol (PGME)/gamma-valerolactone(GVL)=80/18.5/0.5) to give a photoresist solution.

EXAMPLE 7

1.1156 g of poly(EAdMA/ECPMA/HAdA/α-GBLMA; 15/15/30/40) polymer, 0.0238g of triphenyl cyclo(1,3-perfluoropropane disulfone)imidate, 0.0308 g ofbis(triphenylsulfonium)octafluorobutane disulfonate, 0.0406 g ofoctyloxyphenylphenyl iodonum propyloxyperfluorobutane sulfonate fromExample 2, 0.0042 g of 2,6-diisopropylaniline, 0.0049 g ofN-(t-butoxycarbonyl-L-alanine)methylester, and 0.0036 g of a surfactant(fluoroaliphatic polymeric ester, supplied by 3M Corporation, St. PaulMinn.) were dissolved in 28.72 g of mixed solvent MHIB/PGME/GVL(80/18.5/0.5) to give a photoresist solution.

EXAMPLE 8

A silicon substrate coated with a bottom antireflective coating(B.A.R.C.) was prepared by spin coating the bottom anti-reflectivecoating solution (AZ® ArF-38, B.A.R.C. available from AZ ElectronicMaterials USA Corp., Somerville, N.J.) onto the silicon substrate andbaking at 225° C. for 90 sec. The B.A.R.C film thickness was 87 nm. Thephotoresist solution from Example 6 was then coated on the B.A.R.Ccoated silicon substrate. The spin speed was adjusted such that thephotoresist film thickness was 250 nm, soft baked at 100° C./60 s,exposed with Nikon 306D 0.78NA, ⅘ Annular Illumination and 6% attenuatedphase shift mask. The exposed wafer was post exposure baked (PEB) at110° C./60 s. The imaged photoresist was then developed using a 2.38 wt% aqueous solution of tetramethyl ammonium hydroxide for 30 sec. Theline and space patterns were then observed on a scanning electronmicroscope. The photoresist had a photosensitivity of 52.0 mJ/cm² andhad very good exposure latitude (14.7%), good LER and profile shape for100 nm line.

EXAMPLE 9

A silicon substrate coated with a bottom antireflective coating(B.A.R.C.) was prepared by spin coating the bottom anti-reflectivecoating solution (AZ® ArF-38, B.A.R.C. available from AZ ElectronicMaterials USA Corp., Somerville, N.J.) onto the silicon substrate andbaking at 225° C. for 90 sec. The B.A.R.C film thickness was 87 nm. Thephotoresist solution from Example 7 was then coated on the B.A.R.Ccoated silicon substrate. The spin speed was adjusted such that thephotoresist film thickness was 120 nm, soft baked at 100° C./60 s,exposed with Nikon 306D 0.85NA, Y-dipole Illumination and 6% attenuatedphase shift mask. The exposed wafer was post exposure baked (PEB) at110° C./60 s. The imaged photoresist was then developed using a 2.38 wt% aqueous solution of tetramethyl ammonium hydroxide for 30 sec. Theline and space patterns were then observed on a scanning electronmicroscope. The photoresist had a photosensitivity of 44.5 mJ/cm² andhad very good exposure latitude (11.2%), good LER and profile shape for70 nm trench.

EXAMPLE 10

Examples 4 and 5 can be repeated with the photoacid generators fromExample 2 and similar results are expected.

Examples 4, 6, and 7 can be repeated by substituting the polymer thereinwith one of the following polymers: poly(2-methyl-2-adamantylmethacrylate-co-2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-α-gamma-butyrolactonemethacrylate); poly(2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate); poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate); poly(t-butyl norbornene carboxylate-co-maleicanhydride-co-2-methyl-2-adamantyl methacrylate-co-β-gam ma-butyrolactonemethacrylate-co-methacryloyloxy norbornene methacrylate);poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-β-gamma-butyrolactone methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-methyl-2-adamantylmethacrylate-co-3,5-dihydroxy-1-methacryloxyadamantane-co-α-gamma-butyrolactonemethacrylate); poly(2-methyl-2-adamantylmethacrylate-co-3,5-dimethyl-7-hydroxy adamantylmethacrylate-co-α-gamma-butyrolactone methacrylate);poly(2-methyl-2-adamantylacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-α-gamma-butyrolactonemethacrylate); poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-methyl-2-adamantyl methacrylate-co-β-gamma-butyrolactonemethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-ethylcyclopentylacrylate);poly(2-methyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gam ma-butyrolactone methacrylate);poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-α-gamma-butyrolactonemethacrylate-co-2-ethyl-2-adamantyl methacrylate);poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamantane-co-β-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-methyl-2-adamantyl methacrylate-co-2-ethyl-2-adamantylmethacrylate-co-β-gam ma-butyrolactonemethacrylate-co-3-hydroxy-1-methacryloxyadamantane);poly(2-methyl-2-adamantyl methacrylate-co-2-ethyl-2-adamantylmethacrylate-co-α-gamma-butyrolactonemethacrylate-co-3-hydroxy-1-methacryloxyadamantane);poly(2-methyl-2-adamantyl methacrylate-co-methacryloyloxy norbornenemethacrylate-co-β-gamma-butyrolactone methacrylate);poly(ethylcyclopentylmethacrylate-co-2-ethyl-2-adamantylmethacrylate-co-α-gamma-butyrolactone acrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-isobutyl methacrylate-co-α-gamma-butyrolactone acrylate);poly(2-methyl-2-adamantyl methacrylate-co-β-gamma-butyrolactonemethacrylate-co-3-hydroxy-1-adamantylacrylate-co-tricyclo[5,2,1,02,6]deca-8-yl methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactone acrylate); poly(2-methyl-2-adamantylmethacrylate-co-βgamma-butyrolactone methacrylate-co-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamatane);poly(2-methyl-2-adamantyl methacrylate-co-methacryloyloxy norbornenemethacrylate-co-β-gamma-butyrolactone methacrylate-co-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamatane);poly(2-methyl-2-adamantyl methacrylate-co-methacryloyloxy norbornenemethacrylate-co-tricyclo[5,2,1,02,6]deca-8-ylmethacrylate-co-3-hydroxy-1-methacryloxyadamatane-co-α-gamma-butyrolactonemethacrylate); poly(2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-adamantylacrylate-co-tricyclo[5,2,1,02,6]deca-8-ylmethacrylate-co-α-gamma-butyrolactone methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactone acrylate); poly(2-methyl-2-adamantylmethacrylate-co-3-hydroxy-1-methacryloxyadamatane-co-α-gamma-butyrolactonemethacrylate-co-2-ethyl-2-adamantyl-co-methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactonemethacrylate-co-tricyclo[5,2,1,0^(2,6)]deca-8-yl methacrylate);poly(2-ethyl-2-adamantyl methacrylate-co-3-hydroxy-1-adamantylacrylate-co-α-gamma-butyrolactone methacrylate-co-2-adamantylmethacrylate); poly(2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-adamantyl acrylate-co-α-gamma-butyrolactonemethacrylate); and poly(2-ethyl-2-adamantylmethacrylate-co-3-hydroxy-1-adamantyl acrylate-co-α-gamma-butyrolactoneacrylate-co-tricyclo[5,2,1,02,6]deca-8-yl methacrylate)

to form a photoresist solution. The photoresist solutions formedtherefrom are expected to give similar results as to those found inExamples 5, 8 and 9.

The additional photoacid generators of formula (Ai)₂ Xi1 can be made inaccordance with the procedures set forth in U.S. patent application Ser.Nos. 11/179,886, filed Jul. 12, 2005, and Ser. No. 11/355,762, filedFeb. 16, 2006, the contents of which are hereby incorporated herein byreference. Other examples are found in U.S. patent application Ser. No.11/355,400, filed Feb. 16, 2006, United States Published PatentApplication 2004-0229155, and United States Published Patent Application2005-0271974, U.S. Pat. No. 5,837,420, U.S. Pat. No. 6,111,143, and U.S.Pat. No. 6,358,665, the contents of which are hereby incorporated hereinby reference. Those additional photoacid generators of formula Ai Xi2are well known to those skilled in the art, for example, those knownfrom United States Patent Application No. 20030235782 and United StatesPatent Application No. 20050271974, the contents of which are herebyincorporated herein by reference.

The foregoing description of the invention illustrates and describes thepresent invention. Additionally, the disclosure shows and describes onlycertain embodiments of the invention but, as mentioned above, it is tobe understood that the invention is capable of use in various othercombinations, modifications, and environments and is capable of changesor modifications within the scope of the inventive concept as expressedherein, commensurate with the above teachings and/or the skill orknowledge of the relevant art. The embodiments described hereinabove arefurther intended to explain best modes known of practicing the inventionand to enable others skilled in the art to utilize the invention insuch, or other, embodiments and with the various modifications requiredby the particular applications or uses of the invention. Accordingly,the description is not intended to limit the invention to the formdisclosed herein. Also, it is intended that the appended claims beconstrued to include alternative embodiments.

1. A compound of the formula

where X is selected from the group CF₃SO₃, C₄F₉SO₃, N(SO₂C₂F₅)₂,N(SO₂CF₃SO₂C₄F₉), N(SO₂C₃F₇)₂, N(SO₂C₄F₉)₂, CF₃CHFO(CF₂)₂SO₃, andCH₃CH₂CH₂O(CF₂)₄SO₃.
 2. A photoresist composition comprising; a) apolymer containing an acid labile group; b) a compound having theformula

where X is selected from the group CF₃SO₃, C₄F₉SO₃, N(SO₂CF₃)₂,N(SO₂C₂F₅)₂, N(SO₂CF₃SO₂C₄F₉), N(SO₂C₃F₇)₂, N(SO₂C₄F₉)₂, C(SO₂CF₃)₃,CF₃CHFO(CF₂)₂SO₃, and CH₃CH₂CH₂O(CF₂)₄SO₃; and c) one or more additionalphotoacid generators.
 3. The composition of claim 2, wherein c) the oneor more additional photoacid generators are selected from (a) a compoundof the formula(Ai)₂ Xi1, where each Ai is individually an organic onium cationselected from

where Ar is selected from

 naphthyl, or anthryl; Y is selected from

where R₁, R₂, R₃, R_(1A), R_(1B), R_(2A), R_(2B), R_(3A), R_(3B),R_(4A), R_(4B), R_(5A), and R_(5B) are each independently selected fromZ, hydrogen, OSO₂R₉, OR₂₀, straight or branched alkyl chain optionallycontaining one or more O atoms, monocycloalkyl or polycycloalkyl groupoptionally containing one or more O atoms, monocycloalkyl- orpolycycloalkylcarbonyl group, aryl, aralkyl, arylcarbonylmethyl group,alkoxyalkyl, alkoxycarbonylalkyl, alkylcarbonyl, monocycloalkyl- orpolycycloalkyloxycarbonylalkyl with the cycloalkyl ring optionallycontaining one or more O atoms, monocycloalkyl- orpolycycloalkyloxyalkyl with the cycloalkyl ring optionally containingone or more O atoms, straight or branched perfluoroalkyl,monocycloperfluoroalkyl or polycycloperfluoroalkyl, straight or branchedalkoxy chain, nitro, cyano, halogen, carboxyl, hydroxyl, sulfate,tresyl, or hydroxyl; R₆ and R₇ are each independently selected fromstraight or branched alkyl chain optionally containing one or more Oatoms, monocycloalkyl or polycycloalkyl group optionally containing oneor more O atoms, monocycloalkyl- or polycycloalkylcarbonyl group, aryl,aralkyl, straight or branched perfluoroalkyl, monocycloperfluoroalkyl orpolycycloperfluoroalkyl, arylcarbonylmethyl group, nitro, cyano, orhydroxyl or R₆ and R₇ together with the S atom to which they areattached form a 5-, 6-, or 7-membered saturated or unsaturated ringoptionally containing one or more O atoms; R₉ is selected from alkyl,fluoroalkyl, perfluoroalkyl, aryl, fluoroaryl, perfluoroaryl,monocycloalkyl or polycycloalkyl group with the cycloalkyl ringoptionally containing one or more O atoms, monocyclofluoroalkyl orpolycyclofluoroalkyl group with the cycloalkyl ring optionallycontaining one or more O atoms, or monocycloperfluoralkyl orpolycycloperfluoroalkyl group with the cycloalkyl ring optionallycontaining one or more O atoms; R₂₀ is alkoxyalkyl, alkoxycarbonylalkyl,alkylcarbonyl, monocycloalkyl- or polycycloalkyloxycarbonylalkyl withthe cycloalkyl ring optionally containing one or more O atoms, ormonocycloalkyl- or polycycloalkyloxyalkyl with the cycloalkyl ringoptionally containing one or more O atoms; T is a direct bond, adivalent straight or branched alkyl group optionally containing one ormore O atoms, divalent aryl group, divalent aralkyl group, or divalentmonocycloalkyl or polycycloalkyl group optionally containing one or moreO atoms; Z is —(V)_(j)—(C(X11)(X12))_(n)-O—C(═O)—R₈, where either (i)one of X11 or X12 is straight or branched alkyl chain containing atleast one fluorine atom and the other is hydrogen, halogen, or straightor branched alkyl chain or (ii) both of X11 and X12 are straight orbranched alkyl chain containing at least one fluorine atom; V is alinkage group selected from a direct bond, a divalent straight orbranched alkyl group optionally containing one or more O atoms, divalentaryl group, divalent aralkyl group, or divalent monocycloalkyl orpolycycloalkyl group optionally containing one or more O atoms; X2 ishydrogen, halogen, or straight or branched alkyl chain optionallycontaining one or more O atoms; R₈ is a straight or branched alkyl chainoptionally containing one or more O atoms, a monocycloalkyl orpolycycloalkyl group optionally containing one or more O atoms, or aryl;X3 is hydrogen, straight or branched alkyl chain, halogen, cyano, or—C(═O)—R₅₀ where R₅₀ is selected from straight or branched alkyl chainoptionally containing one or more O atoms or —O—R₅₁ where R₅₁ ishydrogen or straight or branched alkyl chain; each of i and k areindependently 0 or a positive integer; j is 0 to 10; m is 0 to 10; and nis 0 to 10, the straight or branched alkyl chain optionally containingone or more O atoms, straight or branched alkyl chain, straight orbranched alkoxy chain, monocycloalkyl or polycycloalkyl group optionallycontaining one or more O atoms, monocycloalkyl- orpolycycloalkylcarbonyl group, alkoxyalkyl, alkoxycarbonylalkyl,alkylcarbonyl, monocycloalkyl- or polycycloalkyloxycarbonylalkyl withthe cycloalkyl ring optionally containing one or more O atoms,monocycloalkyl- or polycycloalkyloxyalkyl with the cycloalkyl ringoptionally containing one or more O atoms, aralkyl, aryl, naphthyl,anthryl, 5-, 6-, or 7-membered saturated or unsaturated ring optionallycontaining one or more O atoms, or arylcarbonylmethyl group beingunsubstituted or substituted by one or more groups selected from thegroup consisting of Z, halogen, alkyl, C₁₋₈ perfluoroalkyl,monocycloalkyl or polycycloalkyl, OR₂₀, alkoxy, C₃₋₂₀ cyclic alkoxy,dialkylamino, dicyclic dialkylamino, hydroxyl, cyano, nitro, tresyl,oxo, aryl, aralkyl, oxygen atom, CF₃SO₃, aryloxy, arylthio, and groupsof formulae (II) to (VI):

wherein R₁₀ and R₁₁ each independently represent a hydrogen atom, astraight or branched alkyl chain optionally containing one or more Oatoms, or a monocycloalkyl or polycycloalkyl group optionally containingone or more O atoms, or R₁₀ and R₁₁ together can represent an alkylenegroup to form a five- or six-membered ring; R₁₂ represents a straight orbranched alkyl chain optionally containing one or more O atoms, amonocycloalkyl or polycycloalkyl group optionally containing one or moreO atoms, or aralkyl, or R₁₀ and R₁₂ together represent an alkylene groupwhich forms a five- or six-membered ring together with the interposing—C—O— group, the carbon atom in the ring being optionally substituted byan oxygen atom; R₁₃ represents a straight or branched alkyl chainoptionally containing one or more O atoms or a monocycloalkyl orpolycycloalkyl group optionally containing one or more O atoms; R₁₄ andR₁₅ each independently represent a hydrogen atom, a straight or branchedalkyl chain optionally containing one or more O atoms or amonocycloalkyl or polycycloalkyl group optionally containing one or moreO atoms; R₁₆ represents a straight or branched alkyl chain optionallycontaining one or more O atoms, a monocycloalkyl or polycycloalkyl groupoptionally containing one or more O atoms, aryl, or aralkyl; and R₁₇represents straight or branched alkyl chain optionally containing one ormore O atoms, a monocycloalkyl or polycycloalkyl group optionallycontaining one or more O atoms, aryl, aralkyl, the group —Si(R₁₆)₂R₁₇,or the group —O—Si(R₁₆)₂R₁₇, the straight or branched alkyl chainoptionally containing one or more O atoms, monocycloalkyl orpolycycloalkyl group optionally containing one or more O atoms, aryl,and aralkyl being unsubstituted or substituted as above; Xi1 is an anionof the formulaQ-R₅₀₀—SO₃ ⁻ where Q is selected from O₃S and O₂C; R₅₀₀ is a groupselected from linear or branched alkyl, cycloalkyl, aryl, orcombinations thereof, optionally containing a catenary S or N, where thealkyl, cycloalkyl, and aryl groups are unsubstituted or substituted byone or more groups selected from the group consisting of halogen,unsubstituted or substituted alkyl, unsubstituted or substituted C₁₋₈perfluoroalkyl, hydroxyl, cyano, sulfate, and nitro; and (b) a compoundhaving the formulaAi Xi2, where Ai is an organic onium cation as previously defined andXi2 is an anion; and mixtures of (a) and (b) thereof.
 4. The compositionof claim 3, wherein Xi2 is selected from selected from CF₃SO₃ ⁻, CHF₂SO₃⁻, CH₃SO₃ ⁻, CCl₃SO₃ ⁻, C₂F₅SO₃ ⁻, C₂HF₄SO₃ ⁻, C₄F₉SO₃ ⁻, camphorsulfonate, perfluorooctane sulfonate, benzene sulfonate,pentafluorobenzene sulfonate, toluene sulfonate, perfluorotoluenesulfonate, (Rf1SO₂)₃C⁻ and (Rf1SO₂)₂N⁻, wherein each Rf1 isindependently selected from the group consisting of highly fluorinatedor perfluorinated alkyl or fluorinated aryl radicals and may be cyclic,when a combination of any two Rf1 groups are linked to form a bridge,further, the Rf1 alkyl chains contain from 1-20 carbon atoms and may bestraight, branched, or cyclic, such that divalent oxygen, trivalentnitrogen or hexavalent sulfur may interrupt the skeletal chain, furtherwhen Rf1 contains a cyclic structure, such structure has 5 or 6 ringmembers, optionally, 1 or 2 of which are heteroatoms, and Rg-O—Rf2-SO₃⁻, where Rf2 is selected from the group consisting of linear or branched(CF₂)_(j) where j is an integer from 4 to 10 and C₁-C₁₂cycloperfluoroalkyl divalent radical which is optionallyperfluoroC₁₋₁₀alkyl substituted, Rg is selected from the groupconsisting of C₁-C₂₀ linear, branched, monocycloalkyl or polycycloalkyl,C₁-C₂₀ linear, branched, monocycloalkenyl or polycycloalkenyl, aryl, andaralkyl, the alkyl, alkenyl, aralkyl and aryl groups beingunsubstituted, substituted, optionally containing one or more catenaryoxygen atoms, partially fluorinated or perfluorinated.
 5. Thecomposition of claim 4 wherein the anion Xi2 is selected from include(C₂F₅SO₂)₂N⁻, (C₄F₉SO₂)₂N⁻, (C₈F₁₇SO₂)₃C⁻, (CF₃SO₂)₃C⁻, (CF₃SO₂)₂N⁻,(CF₃SO₂)₂(C₄F₉SO₂)C⁻, (C₂F₅SO₂)₃C⁻, (C₄F₉SO₂)₃C⁻, (CF₃SO₂)₂(C₂F₅SO₂)C⁻,(C₄F₉SO₂)(C₂F₅SO₂)₂C⁻, (CF₃SO₂)(C₄F₉SO₂)N⁻, [(CF₃)₂NC₂F₄SO₂]₂N⁻,(CF₃)₂NC₂F₄SO₂C⁻ (SO₂CF₃)₂, (3,5-bis(CF₃)C₆H₃)SO₂N⁻SO₂CF₃, C₆F₅SO₂C⁻(SO₂CF₃)₂, C₆F₅SO₂N⁻SO₂CF₃,

CF₃CHFO(CF₂)₄SO₃ ⁻, CF₃CH₂O(CF₂)₄SO₃ ⁻, CH₃CH₂O(CF₂)₄SO₃ ⁻,CH₃CH₂CH₂O(CF₂)₄SO₃ ⁻, CH₃O(CF₂)₄SO₃ ⁻, C₂H₅O(CF₂)₄SO₃ ⁻, C₄H₉O(CF₂)₄SO₃⁻, C₆H₅CH₂O(CF₂)₄SO₃ ⁻, C₂H₅OCF₂CF(CF₃)SO₃ ⁻, CH₂═CHCH₂O(CF₂)₄SO₃ ⁻,CH₃OCF₂CF(CF₃)SO₃ ⁻, C₄H₉OCF₂CF(CF₃)SO₃ ⁻, C₈H₁₇O(CF₂)₂SO₃ ⁻, andC₄H₉O(CF₂)₂SO₃ ⁻.
 6. The composition of claim 2, wherein c) the one ormore additional photoacid generators are selected from the groupbis(4-t-butylphenyl) iodonium triphenyl sulfoniumperfluorobutane-1,4-disulfonate, bis(4-t-butylphenyl) iodonium triphenylsulfonium perfluoropropane-1,3-disulfonate, bis(4-t-butylphenyl)iodonium triphenyl sulfonium perfluoropropane-1-carboxylate-3-sulfonate,bis(4-t-butylphenyl) iodonium triphenyl sulfoniumperfluorobutane-1-carboxylate-4-sulfonate, bis(4-t-butylphenyl) iodoniumtriphenyl sulfonium perfluoromethane disulfonate, bis(4-t-butylphenyl)iodonium triphenyl sulfonium methane disulfonate, bis(4-t-butylphenyl)iodonium triphenyl sulfonium perfluoroethane disulfonate,bis(4-t-butylphenyl) iodonium triphenyl sulfonium ethane disulfonate,bis(triphenyl sulfonium) perfluorobutane-1,4-disulfonate, bis(triphenylsulfonium) perfluoropropane-1,3-disulfonate,bis(benzoyltetramethylenesulfonium) perfluoropropane-1,3-disulfonate,bis(benzoyltetramethylenesulfonium) perfluorobutane-1,4-disulfonate,bis(tris(4-t-butylphenyl) sulfonium) perfluorobutane-1,4-disulfonate,bis(tris(4-t-butylphenyl) sulfonium) perfluoropropane-1,3-disulfonate,bis(4-t-butylphenyldiphenyl sulfonium) perfluorobutane-1,4-disulfonate,bis(4-t-butylphenyldiphenyl sulfonium) perfluoropropane-1,3-disulfonate,bis(triphenyl sulfonium) perfluoropropane-1-carboxylate-3-sulfonate,bis(triphenyl sulfonium) perfluorobutane-1-carboxylate-4-sulfonate,bis(benzoyltetramethylenesulfonium)perfluoropropane-1-carboxylate-3-sulfonate,bis(benzoyltetramethylenesulfonium)perfluorobutane-1-carboxylate-4-sulfonate, bis(tris(4-t-butyl phenyl)sulfonium) perfluoropropane-1-carboxylate-3-sulfonate,bis(tris(4-t-butyl phenyl) sulfonium)perfluorobutane-1-carboxylate-4-sulfonate, bis(4-t-butylphenyl diphenylsulfonium) perfluoropropane-1-carboxylate-3-sulfonate,bis(4-t-butylphenyl diphenyl sulfonium)perfluorobutane-1-carboxylate-4-sulfonate, bis(4-t-butylphenyl iodonium)methane disulfonate, bis(triphenyl sulfonium) methane disulfonate,bis(4-t-butylphenyl iodonium) perfluoromethane disulfonate,bis(triphenyl sulfonium) perfluoromethane disulfonate,bis(benzoyltetramethylenesulfonium) perfluoromethane disulfonate,bis(benzoyl-tetramethylene-sulfonium) methane disulfonate,bis(tris(4-t-butyl phenyl) sulfonium) perfluoromethane disulfonate,bis(tris(4-t-butyl phenyl) sulfonium) methane disulfonate,bis(4-t-butylphenyl diphenylsulfonium) perfluoromethane disulfonate,bis(4-t-butylphenyl diphenylsulfonium) methane disulfonate,bis(4-octyloxyphenyl) iodonium perfluorobutane-1,4-disulfonate,bis(4-octyloxyphenyl) iodonium ethane disulfonate, bis(4-octyloxyphenyl)iodonium perfluoroethane disulfonate, bis(4-octyloxyphenyl) iodoniumperfluoropropane-1,3-disulfonate, bis(4-octyloxyphenyl) iodoniumperfluoropropane-1-carboxylate-3-sulfonate, bis(4-octyloxyphenyl)iodonium perfluorobutane-1-carboxylate-4-sulfonate,bis(4-octyloxyphenyl) iodonium methane disulfonate,bis(4-octyloxyphenyl) iodonium perfluoromethane disulfonate,bis(4-octyloxyphenyl) phenyl sulfonium perfluorobutane-1,4-disulfonate,bis(4-octyloxyphenyl) phenyl sulfonium ethane disulfonate,bis(4-octyloxyphenyl) phenyl sulfonium perfluoroethane disulfonate,bis(4-octyloxyphenyl) phenyl sulfonium perfluoropropane-1,3-disulfonate,bis(4-octyloxyphenyl) phenyl sulfoniumperfluoropropane-1-carboxylate-3-sulfonate, bis(4-octyloxyphenyl) phenylsulfonium perfluorobutane-1-carboxylate-4-sulfonate,bis(4-octyloxyphenyl) phenyl sulfonium methane disulfonate,bis(4-octyloxyphenyl) phenyl sulfonium perfluoromethane disulfonate,bis[bis[4-pentafluorobenzenesulfonyloxy-phenyl]phenylsulfonium]perfluorobutane-1,4-disulfonate,bis[bis[4-pentafluoro-benzene-sulfonyloxyphenyl]phenylsulfonium]ethanedisulfonate,bis[bis[4-pentafluorobenzenesulfonyloxyphenyl]phenyl-sulfonium]perfluoroethanedisulfonate,bis[bis[4-pentafluorobenzene-sulfonyloxyphenyl]phenylsulfonium]perfluoropropane-1,3-disulfonate,bis[bis[4-pentafluorobenzenesulfonyloxyphenyl]phenylsulfonium]perfluoropropane-1-carboxylate-3-sulfonate,bis[bis[4-pentafluorobenzenesulfonyloxy-phenyl]phenylsulfonium]perfluorobutane-1-carboxylate-4-sulfonate,bis[bis[4-pentafluorobenzenesulfonyloxyphenyl]phenylsulfonium]methanedisulfonate,bis[bis[4-pentafluorobenzenesulfonyloxyphenyl]phenylsulfonium]perfluoromethanedisulfonate,bis[bis[4-(3,5-di(trifluoromethyl)benzenesulfonyloxy)-phenyl]phenylsulfonium]perfluorobutane-1,4-disulfonate,bis[bis[4-(3,5-di(trifluoromethyl)benzenesulfonyloxy)phenyl]phenylsulfonium]ethanedisulfonate,bis[bis[4-(3,5-di(trifluoromethyl)benzenesulfonyloxy)phenyl]phenylsulfonium]perfluoroethanedisulfonate,bis[bis[4-(3,5-di(trifluoromethyl)benzenesulfonyloxy)phenyl]phenylsulfonium]perfluoropropane-1,3-disulfonate,bis[bis[4-(3,5-di(trifluoro-methyl)benzenesulfonyloxy)phenyl]phenylsulfonium]perfluoropropane-1-carboxylate-3-sulfonate,bis[bis[4-(3,5-di(trifluoromethyl)benzenesulfonyloxy)-phenyl]phenylsulfonium]perfluorobutane-1-carboxylate-4-sulfonate,bis[bis[4-(3,5-di(trifluoromethyl)benzenesulfonyloxy)phenyl]phenylsulfonium]methanedisulfonate, bis(4-t-butylphenyl iodonium) ethane disulfonate,bis(4-t-butylphenyl iodonium) perfluoroethane disulfonate, bis(triphenylsulfonium) ethane disulfonate, bis(triphenyl sulfonium) perfluoroethanedisulfonate, bis(benzoyltetramethylene-sulfonium) perfluoroethanedisulfonate, bis(benzoyltetramethylenesulfonium) ethane disulfonate,bis(tris(4-t-butyl phenyl) sulfonium) perfluoroethane disulfonate,bis(tris(4-t-butyl phenyl) sulfonium) ethane disulfonate,bis(4-t-butylphenyl diphenylsulfonium) perfluoroethane disulfonate,bis(4-t-butylphenyl diphenylsulfonium) ethane disulfonate,bis[bis[2-methyladamantylacetyloxymethoxyphenyl]phenyl-sulfonium]perfluorobutane-1,4-disulfonate,bis[bis[2-methyladamantylacetyloxymethoxyphenyl]phenylsulfonium]ethanedisulfonate,bis[bis[2-methyladamantylacetyloxymethoxyphenyl]phenylsulfonium]perfluoroethanedisulfonate,bis[bis[2-methyladamantylacetyloxymethoxyphenyl]phenylsulfonium]perfluoropropane-1,3-disulfonate,bis[bis[2-methyladamantylacetyloxymethoxyphenyl]phenylsulfonium]perfluoropropane-1-carboxylate-3-sulfonate,bis[bis[2-methyl-adamantylacetyloxymethoxyphenyl]phenylsulfonium]perfluorobutane-1-carboxylate-4-sulfonate,bis[bis[2-methyladamantylacetyloxymethoxyphenyl]phenylsulfonium]methanedisulfonate,bis[bis[2-methyladamantylacetyloxy-methoxyphenyl]phenylsulfonium]perfluoromethanedisulfonate,bis[bis[4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0^(2,5)]-nonylmethoxyphenyl]phenylsulfonium]perfluorobutane-1,4-disulfonate,bis[bis[4,4-bis(trifluoromethyl)-3-oxatricyclo-[4.2.1.0^(2,5)]-nonylmethoxy-phenyl]phenylsulfonium]ethane disulfonate,bis[bis[4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0^(2,5)]-nonylmethoxyphenyl]phenylsulfonium]-perfluoroethane disulfonate,bis[bis[4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0^(2,5)]-nonylmethoxy-phenyl]phenylsulfonium]perfluoropropane-1,3-disulfonate,bis[bis[4,4-bis(trifluoro-methyl)-3-oxatricyclo[4.2.1.0^(2,5)]-nonylmethoxyphenyl]phenylsulfonium]-perfluoropropane-1-carboxylate-3-sulfonate,bis[bis[4,4-bis(trifluoro-methyl)-3-oxatricyclo[4.2.1.0^(2,5)]-nonylmethoxyphenyl]phenylsulfonium]perfluoro-butane-1-carboxylate-4-sulfonate,bis[bis[4,4-bis(trifluoromethyl)-3-oxatricyclo-[4.2.1.0^(2,5)]-nonylmethoxyphenyl]phenylsulfonium]methane disulfonate,bis[bis[4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0^(2,5)]-nonylmethoxyphenyl]phenylsulfonium]perfluoromethane disulfonate, bis(4-t-butylphenyl) iodoniumbis-perfluoroethane sulfonimide, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluorobutane sulfonate,triphenylsulfonium trifluromethane sulfonate, triphenylsulfoniumnonafluorobutane sulfonate, 4-(1-butoxyphenyl)diphenylsulfoniumbis-(perfluorobutanesulfonyl)imide, 4-(1-butoxyphenyl)diphenylsulfoniumbis-(perfluoroethanesulfonyl)imide,2,4,6-trimethylphenyldiphenylsulfoniumbis-perfluorobutanesulfonyl)imide,2,4,6-trimethylphenyldiphenylsulfoniumbis-(perfluoroethanesulfonyl)imide, toluenediphenylsulfoniumbis-(perfluorobutanesulfonyl)imide, toluenediphenylsulfoniumbis-(perfluoroethanesulfonyl)imide,toluenediphenylsulfonium-(trifluoromethyl perfluorobutylsulfonyl)imide,tris-(tert-butylphenyl)sulfonium-(trifluoromethylperfluorobutylsulfonyl)imide, tris-(tert-butylphenyl)sulfoniumbis-(perfluorobutanesulfonyl)imide,tris-(tert-butylphenyl)sulfonium-bis-(trifluoromethanesulfonyl)imide,and mixtures thereof.
 7. A process for imaging a photoresist comprisingthe steps of: include a) applying a coating layer a substrate with thecomposition of claim 2; b) baking the substrate to substantially removethe solvent; c) image-wise exposing the photoresist coating; d)optionally, postexposure baking the photoresist coating; and e)developing the photoresist coating with an aqueous alkaline solution. 8.A coated substrate comprising a substrate with a photoresist coatingfilm, wherein the photoresist coating film is formed from thephotoresist composition of claim 7.